This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-157881, Jun. 4, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a photometry and distance measuring unit, and more particularly to a compact photometry and distance measuring unit which can reduce the influence of noises of a feeble-signal system.
A photometry and distance measuring unit detects feeble light from an object. The size of the unit depends on an arrangement of an optical system or an electrical element for the purpose of detection.
For example, it is known to arrange a photometry sensor between a light transmitting unit and a light receiving unit of an active AF (auto focus) device, as disclosed in Jpn. UM Appln. KOKAI Publication No. 6-18930. According to this arrangement, the space between light beams transmitted between the light transmitting unit and the light receiving unit can be effectively utilized.
In recent years, however, the equipment, such as cameras, has been more and more compact. Accordingly, the space between the light transmitting unit and the light receiving unit of an active AF device is reduced, or another member is interposed between the units. Thus, further space saving has been required.
Moreover, it is necessary to take into consideration that the photometry and distance measuring unit treats a feeble electrical signal.
Accordingly, an object of the present invention is to provide a compact and high-performance photometry/distance measuring unit.
According to a first aspect of the present invention, there is provided a photometry/distance measuring unit having photometry and distance measuring functions, comprising:
a distance measuring photoelectric converting element; and
a processing circuit formed on a chip independent of the distance measuring photoelectric converting element and including on one surface thereof a photometry photoelectric converting portion and a signal processing portion for processing an output from the distance measuring photoelectric converting element.
According to a second aspect of the present invention, there is provided a one-chip semiconductor element comprising:
(a) a photometry photoelectric converting element for outputting an electric signal in accordance with an amount of received light; and
(b) a processing circuit for processing a signal detected outside the semiconductor element in order to detect a distance to an object.
According to a third aspect of the present invention, there is provided a camera having photometry and distance measuring functions, comprising:
a light projecting element for projecting distance measuring light to an object;
a first light receiving sensor for receiving the distance measuring light reflected by the object; and
a one-chip semiconductor element including:
(a) a second light receiving sensor for receiving light from a predetermined region of a photographing area; and
(b) a distance measuring circuit for calculation-processing an output signal from the first light receiving sensor.
According to a fourth aspect of the present invention, there is provided a distance measuring apparatus comprising:
a first chip including a distance measuring photoelectric converting element for receiving light passed through an optical system; and
a second chip including a signal processing circuit for processing an output signal from the distance measuring photoelectric converting element, the second chip being arranged on a side of the optical system for guiding light to the first chip.
According to a fifth aspect of the present invention, there is provided a photodetecting apparatus for detecting light and performing a predetermined calculation process based on a result of detection, comprising:
a first chip including a first photosensor;
a second chip independent of the first chip, including:
(a) a second photosensor; and
(b) a processing circuit for calculation-processing an output signal from the first photosensor.
According to a sixth aspect of the present invention, there is provided a camera having a distance measuring apparatus, the camera comprising:
a distance measuring light receiving element having a light receiving surface for receiving light from an object to detect a distance to the object, a light receiving position on the light receiving surface being varied in a predetermined direction in accordance with the distance to the object; and
a processing circuit, arranged perpendicular to the predetermined direction in which the light receiving position on the light receiving surface is varied, for performing a predetermined process for detecting the distance to the object based on an output signal from the distance measuring light receiving element.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.